Relatively recent technical advances have resulted in the use of several technologies in a one product. For example, mobile devices, such as mobile telephones, portable computing devices, personal digital assistants (PDAs), and the like may include electronic circuitry as well optical functionality.
The use of both electronic circuitry and optical functionality allows the device to provide new features, additional functionality, and/or convenience. For example, a device may sense ambient light levels and adjust display contrast or brightness accordingly. As another example, a device may sense proximity to an object or user, and turn off or turn on the display (e.g., a mobile telephone may turn off the display when the user holds the telephone close to his/her face or ear).